Myth - Pee on jellyfish sting - Since you are far more likely to suffer a jellyfish sting than a shark bite, know this: Peeing is not proven to help jellyfish stings (though testimonials abound). Instead, apply vinegar.

Myth - Slather butter on a burn - Besides the obvious risk of infection, putting butter or any kind of grease on a burn can TRAP heat and cause scarring.